The present disclosure relates to a semiconductor memory device, particularly, to a ternary content addressable memory (TCAM).
In recent years with the Internet in wide use, demand has been increasing for content-addressable memories (CAMs) having an address search function, particularly, ternary content-addressable memories (TCAMs) including memory cells each capable of holding three values, 0, 1, and X. In many cases, TCAMs are used in the system-on-a-chip (SoC) field, particularly, in system LSIs such as routers and network switches (see Japanese Unexamined Patent Application Publications Nos. 2003-272386 and 2002-373494, U.S. Pat. No. 6,154,384, Japanese Unexamined Patent Application Publications Nos. 2003-141879 and Hei 7(1995)-220483, Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2005-501369).